Time switch and valve control



F, 3 w J N w w .6 F

INVENTOR. James B. Mar/.5.

BY ATTORNEY.

Nov. 10, 1942. J- MARls TIME SWITCH AND VALVE CONTROL Original Filed Segfi. 1:, 1939- Fig.5

Patented Nov. 10, 1942 UNITED STATES PATENT OFFlCE TIME SWITCH AND VALVE CONTROL James B. Maris, Glen Ridge, N. .1. Original application September 13, 1939, Serial No. 294,771. Divided and this application June 12, 1940, Serial No. 340,219

4 Claims.

justable cyclic timing means of the type where a synchronous motor driven selective timing means are used to operate electric circuits and pressure valves.

An important object of my invention is to provide a simple, light weight, compact, silent assembly of apparatus which may be used for various types of medical and surgical applications such as draining of wounds, artificial respiration and other pressure and vacuum applications. My invention also represents an improved apparatus for applying intermittent compression of the main arteries as described by Leo 'Buerger, M. D., in The Circulatory Disturbances of the Extremities, W. B. Sounders Company, 1924.

A further object of my invention is to provide an efficient, low cost, silent, synchronous motor driven combination time switch and valve permitting variation of the on and "ofi cycle over a large range.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing, forming part of this specification, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a top view of the timing switch,

Figure 2 is a side view of the same,

Figure'3 represents an end view, and,

Figure 4 represents a section along line 6-6 in Fig. 1.

Figures 1, 2, 3 and 4 show details of the time switch. This switch consists of two plates 26 and 21 held in spaced relation by posts 28 and the valve block 29, and fastened to same with screws or other suitable means. 23 has two inlet connections 30 on one side, suitable for permanent connection by rubber hose, and two outlet connections 3| on the other side. In the preferred arrangement illustrated the two outlet connections 3| are threaded tubes containing valves, similar to the Schroder valves used in automobile tubes. These valves are arranged so that when a connection is made to the threaded ends of 3| the valve inside of same is thereby automatically opened and again closed when the outside connection is removed. The valves are designated with numeral 32, see Fig. 1 and Fig. 2.

On the inside face of valve block 23 there are three projecting studs 33, 34 and 35 which are T The valve block 51 rigidly fastened to block 29. A valve stem 36 with a block 31 is slidable in holes in blocks 34 and 35. One end of valve stem 36 carries a cross arm 38 while the other end 39 is tapered to form a needle valve with block 33. The needle valve in block 33 is connected to inlets and outlets 3| and acts as a pressure release valve.

An insulating block 40 is fastened to block 31 by screw 4|. Adjacent to block 40 is mounted a switch comprising the switch springs 42 and 43 both of which are fixed to an insulating support 44 which is mounted on the inside of plate 21. An insulating member 45 holds spring 43 back when spring 42 is removed. The switch, as shown, isa single pole single throw one with one connection made to lug 46 and the otherconnectlon is made to screw 41 in bracket 48 which is connected to spring 42 through two screws penetrating the insulating block 44.

A shaft 49 journalled in plates 26 and 21 carries a revolving cam structure comprising a plu-' rality of disc cams 50 with spacing washers 5| and a driving gear 52 all fastened together into one structure by rivets 53. The cam structure is rotated by a small synchronous motor mounted on the outside of plate 26 with a driving pinion (not shown in drawing) extending through hole 54 into engagement with gear 52.

A second rotatable cam structure is mounted on shaft 55 which is journalled in plates 26 and 21. This cam structure consists of a plurality of disc cams 56 fastened together with notched wheel 51 by rivets 58. The cam discs 56 are essentially circular washers with a portion cut off. The cut edges of the washers are disposed in a definite angular relation to one another to correspond with the notches in wheel 51. Shaft 55 extends through bushing 58a to knob 59 whereby the cam structure may be manually turned. The bushing 58a has a nut 60 whereby the assembled mechanism may be mounted, see Fig. l. A spring 6| is fixed on plate 26 and is in engagement with the notches of wheel 51 which thereby acts as an index for the setting of the cam structure. The cams 56 are angularly displaced in such a manner that only one at a time has its cut-off in the operating position at one time.

A plurality of spring loaded cam levers 62 are pivoted at one end on shaft 63 which is journalled in plates 26 and 21. There is one lever 62 for each cam 50 and 56 and thus there are as many as there are notches in'wheel 51. In the embodiment of my invention shown in the drawing there are six, but any desired number maybe used. The levers 62 are cut at one end to form fingers 54 and each lever has a spring 65 by which it is pulled up tight against cams 50 and 56. Adjacent to cams 50 the levcrs 62 have a cut out portion 61 which makes it possible for the levers to be pulled up as soon as the nose 65 of cams 50 enters the notch of the corresponding lever. Due to the thinness of levers 62 the springs 55 are staggered and a notch 68 in adjacent levers provides clearance.

The operation of my invention is as follows: The desired cycle is set by turning knob 59 until a given cam 56 is in a position where its cut-off portion is in line with a given lever 62. All the other levers are then held back by the uncut peripheries of the other cams 55 and only the selected lever is free to operate. The selected lever is riding upon cam 50 and when the nose 56 of this cam enters notch 61 the lever will be pulled up by spring 65 and finger 64 will press against cross bar 38 pushing same and valve stem 36 upward thus closing the valve. At the same time switch blades 42 and 43 make contact and may be 'used to start a pump motor having a pump furnishing the pressure governed by the valve 39 and the pressure is on. The earns 50 revolve as described supra and the length of time on depends upon the shape of cams 50. Once during each revolution the lever 62 is lifted away from 38 by the cam 50. The valve stem 36 then drops .by the spring action of switch spring 42, the valve opens, the pressure is released and the switch spring 42 moves away from spring 43 thereby opening the switch and stopping the pump motor. The cams 50 are of different shape giving varying periods of on and off and any one of these cams may be selected for use by turning knob 59 to the proper position on a dial. It is thus possible to obtain various pressure curves illustrated in Fig. 2 of my original application as identified above. In the curve shown at the top of said figure the pressure is on" one minute and off five minutes. The following curves show the on period increased to respectively 1.5, 2, 3 and 4 minutes while the off" period is correspondingly reduced to 4.5, 4, 3 and 2 minutes, respectively.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention I claim:

1. A timing mechanism of the character described comprising a frame; a synchronous motor-driven cam structure rotatably mounted in said frame, said cam structure having a plurality of flat disc cams fixed on a central, rotatable shaft journalled in said frame; a plurality of le vers pivoted at one end in said frame and being supported against said cam structure by individual springs; a manually rotatable cam structure mounted in said frame parallel to said mo- -tor-driven cam structure and located between motor-driven cam structure, and

same and the pivoted end of said levers, and control means operable in turn by said levers.

2. A timing mechanism of the character described comprising a frame; a synchronous motor-driven cam structure rotatably mounted in said frame, said cam structure having a plurality of fiat disc cams fixed on a central, rotatable shaft journalled in said frame; a plurality of levers pivoted at one end in said frame and being supported against said cam structure by individual springs; a manually rotatable cam structure mounted in said frame with its'central shaft parallel to the shaft of said motor-driven cam structure and having a similar number of fiat disc cams, said manually rotatable cam structure being located in operable engagement with said levers between the pivoted ends of same and said control means operable by said levers.

3. A timing mechanism of the character described comprising a frame; a synchronous motor-driven cam structure rotatably mounted in said frame, said cam structure having a plurality of fiat disc cams fixed on a central, rotatable shaft journalled in said frame, each one of said disc cams having a given portion of its circumference removed; a plurality of levers pivoted at one end in said frame and being supported againstsaid cam structure by individual springs; a manually rotatable cam structure mounted in said frame with its central shaft parallel to the shaft of said motor-driven cam structure and having a similar number of flat disc cams, said manually operable cam structure being located in operable engagement with said levers at a point between the pivoted ends of same and said motor-driven cam structure, and control means operable in turn by said levers.

4. A timing mechanism of the character described comprising a frame; a synchronous motor-driven cam structure rotatably mounted in said frame, said cam structure having a plurality of fiat disc cams fixed on a central, rotatable shaft journalled in said frame; a plurality of levers pivoted at one end on a transverse shaft in said frame and being supported against said cam structure by individual coil springs, each one of said levers having a notch engageable in a corre sponding notch in said flat disc earns; a manually rotatable cam structure mounted in said frame with its central shaft parallel to the shaft of said motor-driven cam structure and having a similar number of flat disc cams each of which comprise a circular washer having a segment removed, said manually operable cam structure being located in operable engagement with said levers at a point between the pivoted ends of same and said motor-driven cam structure, and control means operable in turn by any one of said levers.

JAMES B. MARIS. 

